JPH01255207A - Manufacture of coil bobbin - Google Patents

Abstract

PURPOSE:To form a coil bobbin excellently without useless material and without inclination of an iron core due to injecting pressure, by providing a stopper which restricts the movement of the iron core to the outside of the laminating direction, and injecting an insulating thermoplastic resin which is fused at high temperature into a gap and grooves through an injecting hole part by a hot runner method. CONSTITUTION:A cavity part 45 for housing an iron core 11 is provided so that a gap 42 matching a drum part 22 of a coil bobbin 19 and grooves 43 and 44 matching a flange parts 23 and 24 are provided. An injecting hole part 48 for injecting an insulating thermoplastic resin which is fused at high temperature into the gap 42 and the grooves 43 and 44 is formed at one side of the molding die 41 in the laminating direction of the iron core 11. A stopper 56 for restricting the outward movement of the iron core 11 in the laminating direction is provided at the other side of the molding die 41 in the laminating direction of the iron core 11 so as to correspond to said injecting hole part 48. The insulating thermosetting resin which is fused at high temperature is injected into the gap 42 and the grooves 43 and 44 through said injecting hole part 48 by a hot runner method. Thus, the coil bobbin 19 is formed as a unitary body. For example, a heater 49 is provided around the injecting hole part 48.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing a coil bobbin in a ballast for a discharge lamp or the like.

<Prior Art> A body part 2 that tightly surrounds the coil winding part of the iron core 1 shown in FIGS. 8 and 9, and a pair of collar parts 3 that protrude from both ends of the body part 2 in the axial direction. When manufacturing a coil bobbin 4 having an integral part, if a molding method with a runner is used as shown in FIG. 8, a part of the runner 6 will be scrapped, resulting in a large amount of wasted material.

Therefore, in order to prevent scrap from occurring, a hot runner method is used, and since the workpiece is small, it is conceivable to provide one injection hole and use a one-point gate as shown in FIG.

<Problems to be Solved by the Invention> However, in the case of FIG. 9, there was a problem in that the iron core 1 was tilted by the injection pressure of the resin from the gate.

In view of the above-mentioned problems, the present invention enables a coil bobbin to be formed satisfactorily without wasting material and without tilting the iron core due to injection pressure.

<Means for Solving the Problems> The technical means of the present invention for solving this technical problem includes a body 22 that tightly surrounds the coil winding portion 12 of the iron core 11, and an axis of the body 22. A pair of collar parts 23 protruding from both ends in the direction
．． 24, in which a gap 42 corresponding to the body 22 of the coil bobbin 19 and a groove 43 corresponding to the flanges 23, 24 are formed inside the molding die 41.
44, a cavity 45 for housing the iron core 11;
In the coil bobbin manufacturing method in which the coil bobbin 19 is formed by injecting thermoplastic insulating resin into the gaps 42 and grooves 43 and 44, the gaps 42 are formed on one side of the molding die 410 and the iron core 11 in the stacking direction.
An injection hole 48 for injecting thermoplastic insulating resin melted at high temperature is formed in the grooves 43 and 44, and the injection hole 48 is formed on the other side of the molding die 41 in the stacking direction of the iron core 11. A stopper 56 is provided to restrict the outward movement of the core 11 in the stacking direction, and a thermoplastic insulating resin molten at high temperature is injected from the injection hole 48 into the gap 42 and the grooves 43 and 44. The hot runner method is used for injection, and the coil bobbin 19 is integrally formed.

<Example> Hereinafter, the present invention will be explained according to the illustrated example.
Figures 7 to 7 show the configuration of a ballast for a discharge lamp. In the figure, 11 is a T-shaped laminated core, which has a coil winding part 12 and a yoke on one end side of the coil winding part 12. Part 13
has. 14 is a U-shaped laminated core that is combined with the laminated core 11. Both iron cores 11 and 14 are made by laminating a predetermined number of silicon steel plates cut into a predetermined shape, and these are combined in a shape to form a gap 15 between them, and the coil winding of the iron core 11 is performed. The portion 12 serves as a central magnetic path, and both leg portions 16 and 17 of the iron core 14 serve as outer magnetic paths.

A coil 18 is wound around the coil winding portion 12 of the iron core 11 via a coil bobbin 19. coil bobbin 19
is insert-molded onto the core 11 from synthetic resin, and includes a body part 22 that tightly fits around the coil winding part 12, and a pair of flanges 23 that protrude from both ends of the body part 22 in the axial direction.
．． It has 24 integrally.

Reference numeral 26 denotes a terminal block, which is integrally provided on the coil bobbin 19 so as to protrude outward in the stacking direction of the yoke portion 13 of the laminated iron core 11. A plurality of terminal mounting holes 27 are provided in the terminal block 26, and terminals are detachably held in the mounting holes 27.

Reference numeral 31 denotes a protruding wall formed integrally with the coil bobbin 19, and is provided along the stacked end surface of the yoke portion 13 on the opposite side from the terminal block 26. Reference numeral 32 denotes a pair of notch grooves provided on the outer end surface of the yoke portion 13, which are formed over the entire length of the yoke portion 13 in the stacking direction. Reference numeral 33 denotes a pair of connecting parts integrally molded on the coil bobbin 19, which close the notch groove 32 and connect the protruding wall 31.
and the terminal block 26 are connected. Therefore, the state in which the terminal block 26 and the protruding wall 31 are fitted onto the laminated core 11 can be reliably maintained by the connecting part 33, and the terminal block 26 and the protruding wall 31 may not warp up from the yoke part 13 or fall down. This can effectively prevent the flange portion 24 from warping or falling down.

35 is a first stopper fitting recess, and the flange 23 of the body 22
It is provided on the inner surface of the side end. A pair of second stopper fitting recesses 36 are provided in the protruding wall 31 so as to reach the iron core 11. 37 is a third stopper fitting recess;
It is provided in the center of the terminal block 26 so as to reach the iron core 11.

Next, a method for manufacturing the coil bobbin 19 will be explained.

As shown in FIG. 1, a cavity in which the iron core 11 is housed has a gap 42 corresponding to the body 22 of the coil bobbin 19 and grooves 43 and 44 corresponding to the flanges 23 and 24, as shown in FIG. In addition to providing the section 45, the gap 42 and the groove 4
Hollow portions 46.47 corresponding to the terminal block 26 and the protruding wall 31 are provided in communication with the terminal block 3.44. Furthermore, molding mold 4
One injection hole 48 communicating between the groove 3 and the outside is formed in the stacking direction of the first iron core 11, and a heater 49 is provided around the injection hole 48.

In addition, a first stopper insertion hole 5 is provided on the other side of the molding die 41 in the stacking direction of the iron core 11 so as to correspond to the injection hole 48.
1, and a pair of second stopper insertion holes 52 communicating with the hollow part 47 are provided on the other side of the iron core 11 in the stacking direction,
Furthermore, a third stopper insertion hole 53 communicating with the hollow portion 46
Set it up.

Next, a third stopper 55 and an iron core 11 are placed in the molding die 41.
At the same time, a first stopper 56 and a pair of second stoppers 57 are inserted into the first stopper insertion hole 51 and each second stopper insertion hole 52 so as to contact the outer ends of the core 11 in the stacking direction. The first stopper 56 and the second stopper 57 move the iron core 11 outward in the stacking direction (
The iron core 11 is held in the stacking direction by the second stopper 57 and the third stopper 55, and the iron core 11 is held immovably in the stacking direction. I'll keep it.

Then, while the periphery of the injection hole 48 is heated by the heater 49, the thermoplastic insulating resin melted at high temperature is injected from the injection hole 48 into the groove 43 using a hot runner method. Then, the coil bobbin 1 is attached to the iron core 11 with an insulating resin layer.
9 are integrally formed. At the same time, a terminal block 26, a protruding wall 31, and a connecting portion 33 are integrally formed on the coil bobbin 19. In addition, at this time, the first to third stoppers 56.57.55
The coil bobbin 19, the protruding wall 31 and the terminal block 26
(1st to 3rd step) aba-fitting recesses 35, 36.3, respectively.
7 is formed.

In the above embodiment, when forming the coil bobbin 19, in addition to the first stopper 56 provided on the other side of the iron core 11 in the stacking direction so as to correspond to the injection hole 48, a second stopper 57 and a second stopper 57 are provided. Three stoppers 55 are provided to restrict the movement of the iron core 11, but instead, the second stopper 57 and the third stopper 55 are omitted, and only the first stopper 56 is used to prevent the iron core 11 from moving outward in the stacking direction. It may also be possible to restrict movement to.

<Effects of the Invention> According to the present invention, injection holes are provided on one side of the molding die 41 in the stacking direction of the iron core 11 for injecting thermoplastic insulating resin melted at high temperature into the gaps 42 and grooves 43, 44. A stomper 56 is provided on the other side of the molding die 41 in the stacking direction of the iron core 11 to correspond to the injection hole 48 and to restrict movement of the iron core 11 outward in the stacking direction. , a gap 42 and a groove 43, 44 from the injection hole 48.
Since the coil bobbin 19 is integrally formed by injecting thermoplastic insulating resin melted at high temperature using a hot runner method, the injection pressure of the resin from the injection hole 48 is lower than that of the iron core 1.
Even if the iron core 11 is pressed outward in the lamination direction, the stopper 56 can reliably restrict the movement of the iron core 11 outward in the lamination direction, thus preventing the iron core 11 from tilting due to injection pressure. , the coil bobbin 19 can be formed well.

Moreover, since the thermoplastic insulating resin is injected using a hot runner method, there is no need to scrap part of the runner, which is the case with conventional methods, eliminating material waste, making it economical and practical. The effect is significant.

[Brief explanation of the drawing]

Fig. 1 is a plan sectional view showing the manufacturing method of the present invention, Fig. 2 is a front view of a ballast having a coil bobbin manufactured by the manufacturing method of the present invention, Fig. 3 is a plan view thereof, and Fig. 4 is a bottom view of the ballast. 5 is a right side view of the same, FIG. 6 is a left side view of the same, and FIG. 7 is a sectional view of the same side. FIG. 8 and FIG. 9 are configuration diagrams showing a conventional example. 11... Laminated iron core, 12... Coil winding part, 19.
...Coil bobbin, 22...Body part, 23.24...
Flange portion, 41... Molding die, 42... Gap, 43.4
4... Groove, 45... Cavity, 48... Injection hole, 49... Heater, 56... First stopper.

Claims (1)

[Claims] (1) Manufacture of a coil bobbin 19 that integrally includes a body portion 22 that tightly surrounds the coil winding portion 12 of the iron core 11 and a pair of flanges 23 and 24 that protrude from both ends of the body portion 22 in the axial direction. In the method, a gap 42 corresponding to the body 22 of the coil bobbin 19 and a groove 43 corresponding to the flanges 23, 24 are formed inside the molding die 41.
44, a cavity 45 for housing the iron core 11;
In the coil bobbin manufacturing method in which the coil bobbin 19 is formed by injecting a thermoplastic insulating resin into the gap 42 and the grooves 43 and 44, the gap 42 is formed on one side of the molding die 41 in the stacking direction of the iron core 11.
An injection hole 48 for injecting thermoplastic insulating resin molten at high temperature is formed in the grooves 43 and 44, and the injection hole 48 is formed on the other side of the molding die 41 in the stacking direction of the iron core 11. A stopper 56 is provided to restrict the outward movement of the core 11 in the stacking direction, and a thermoplastic insulating resin molten at high temperature is injected from the injection hole 48 into the gap 42 and the grooves 43 and 44. A method for manufacturing a coil bobbin, characterized in that the coil bobbin 19 is integrally formed by injection using a hot runner method.